Measurement and control of the thickness of thin films

Industrial Applications of X-Ray Methods for Measuring Plating Thickness

Thickness measurements of thin transparent coatings on thick transparent bases by reflection interferometry are made possible through use of an immersion medium of the same refractive index as the base to intensify interference. A convenient interferometer comprising three essential parts, a “pocket” spectroscope, an incandescent lamp, and a cylindrical immersion tank, is described. Its use for rapid, precise measurements of thickness of single and double layer coatings and films in the range of 0.2 to 50 microns is illustrated with spectra.

Coating thickness measurement by interferometry.

A new diffraction method for the determination of the effective depth of X-ray penetration

New ways to obtain textured substrates based on paramagnetic Ni-W alloys have been found for the creation of coated second-generation high-temperature superconductors (2G HTSs). The influence of the production conditions on texture formation in the Ni-W/TiN system has been studied for Ni-9.5 at % W alloy ribbons with TiN-based coating. It is established that optimization of the conditions of thin TiN-layer deposition makes it possible to obtain quasi-single-crystalline TiN coatings with a cubic texture. These textured Ni-W/TiN substrates admit the epitaxial growth of high-quality HTS films, which ensures high current-carrying capacity of 2G-HTS wires.

Substrates with a cubic texture based on paramagnetic Ni-W alloy ribbons with thin TiN coating for second-generation high-temperature superconductors

A method is described for determining the thickness of thin coatings on crystalline bases by means of an x‐ray source and a Geiger counter, both situated on the same side of the coating. The x‐rays pass through the coating and are reflected at a Bragg diffraction angle from the base, back to the counter, their intensity being reduced by absorption due to the double transmission through the coating. The thickness of the coating is computed from the measured absorption. The method is applicable to coating thicknesses in the range 10−5 to 10−2 centimeter.

L. S. Birks

Papers

Thickness measurement of thin coatings by x-ray absorption